Since its inception, analog telephone service (“Plain Old Telephone Service” or “POTS”) providers have utilized a DC line voltage (“DCLV”) equal to −48V. The DCLV is generated from the telephone system Central Office or from a relay station and is supplied to customers as a constant −48V when the phone is on hook. The DCLV has various purposes including initiating a telephone call and corrosion control along the POTS twisted pair telephone lines.
During occasions of a municipal power outage, telephone service providers use batteries as a backup −48 VDC voltage source in order to maintain telephone service to customers until normal power sources can be restored. Direct current batteries are installed at a myriad of Central Offices and Digital Loop Electronics (“DLE”) Remote Terminal (“RT”) locations along the telephone system in what may be called wire centers. Each wire center may have multiple RT sites, which could be a cabinet or other structure type such as a hut or Controlled Environmental Vault (“CEV”). Each RT site may have a string or multiple strings of batteries in series capable of providing −48 VDC to its segment of the POTS network.
Telephone networks today are extremely large and may consist of tens of thousands of remote sites spread across a number of states. Those remote sites may contain hundreds of thousands if not millions of batteries of different voltages, makes and models. All of those batteries must be tracked to ensure that depleted batteries are replaced, that all sites have a full complement of batteries installed, that installed batteries are compatible with each other and that the proper DCLV is produced when required. Difficulties have arisen in monitoring such a large inventory of batteries by a widely dispersed force of technicians with varying levels of training. Further, manufacturer recalls of defective batteries has also proven problematic as the defective batteries must be culled from the inventory in a timely manner and replaced with compatible substitutes. Failure to maintain battery strings with the requisite −48 VDC DCLV may negatively impact the performance of a telephone system and the cost of holding depleted batteries may be large. Therefore a standardized, computer assisted inventory method is needed to maximize the performance and minimize the cost of maintaining a battery back up system.